Determining meat quality of a live animal

ABSTRACT

A method of providing an indication of pH levels in an animal can alternatively be used to provide an indication of stress in an animal. Since pH and temperature are related to ultimate meat quality, the method of the invention may also be used to provide an indication of ultimate meat quality. In the method, periodic measurements are obtained corresponding to the body temperature of the animal. An algorithm is applied to the measurements obtained. The algorithm cumulatively takes account of variations of body temperature over time. The results of the algorithm are compared to a per-determined threshold. Alternatively, the results of the algorithm may be compared with a standard to provide a quantitative indication of pH, stress or meat tenderness. A system for providing an indication of meat quality/stress levels or pH levels in an animal is also provided.

FIELD OF THE INVENTION

The present invention relates to methods and systems of using animaltemperature measurements to predict meat pH and stress levels, as wellas meat quality in an animal. Also provided are animal identificationtags incorporating temperature sensors. These devices are also useful inmonitoring the physiological state of an animal.

BACKGROUND ART

Livestock stress has long been recognised as having a major impact onthe post-mortem quality of the animal tissue.^(1,2,3,4,5)

It is well known that stress causes the depletion of an animal's energyreserves through depletion of glycogen in muscle tissue, and causes anincrease in pH. pH values in excess of 5.8 result in poor meat quality.PH values in the range 5.8-6.1 cause toughness and furthermore, valuesin the range 5.8-7.00 cause increasing deterioration ^(A, B, C).Qualities affected include:

Colour: the higher the ultimate pH the darker the meat colour. Customerdemand is for bright red, rather than dark, meats;

Keeping ability: which decreases with the increase in pH;

Texture: high pHs tend to produce rubbery, watery meats; and

Tenderness: both high and low pH meats may be tender.

However, because of the other disadvantages associated with high pH, lowpH tender meat is preferable. High pH, poor quality meats are notsuitable for the export market and are often down-graded resulting inmulti-million dollar losses to the primary meat sector each year.

Major causes of stress include rounding up and lairage of animals on thefarm, crowded transport conditions, driving animals over long distanceswithout rest, and handling procedures at processing plants, such asprodding and washing. It has also been recognised that by feeding ananimal prior to slaughter, muscle energy reserves can be restored anddown-grading avoided.⁴ In ruminant animal such replenishment can takemore than a day. In a monogastric, this is normally quicker. If atechnology existed that could recognise at risk animals prior toprocessing then these animals could be treated.

U.S. Pat. No. 5,458,418, and U.S. Pat. No. 5,595,444 disclose methods ofdetecting poor meat quality in animals using infrared thermography. Asingle thermographic temperature measure is taken of an animal prior toslaughter. Animals with a thermograph outside a a predetermined testtemperature range are rejected as likely to have meat of poor quality.Similarly, for a group of animals, animals showing a significantdeviation in mean image temperature compared to the group meantemperature are rejected as likely to have meat of poor quality.

The infrared thermography methods disclosed in these patents are subjectto a number of drawbacks. A one point temperature measurement prior toslaughter cannot reflect thermal history, nor accurately predict itseffect on meat quality. The single reading may detect acute stressshortly prior to slaughter but not cumulative stress over a period oftime. A further drawback is that an animal may be rejected for slaughteras a consequence of its mean image temperature in comparison with thegroup and not by reference to an absolute standard. Thus, animals may beunnecessarily downgraded. It is for this reason that infraredthermography has not performed well in practice as a predictor of meatquality.

It is an object of the present invention to provide a method foridentifying stressed animals, or at least to provide the public with auseful choice.

The present applicant has found that in all animals subjected to stress,body temperature changes produce either an increase or decrease in skinheat loss. Changes in body temperature both up and down from thehomeostatic norm are energetic that is energy must be used tore-establish norm by pulling body temperature up or lowering it (heatproduction or heat loss). Often these adjustments are quick and notreflected in deep body temperatures. They are, however, reflected inskin and surface temperatures and peripheral blood flow mechanisms ie.in the outer body. High energy expenditure can be made with littlechange seen in core temperatures. Falls in body/skin temperature are as(if not more) energetically demanding than rises.

In terms of stress measurement both a fall, or rise, in skin/bodytemperature can be an important indicator of stress, and such changescan be important both acutely and chronically (i.e. a number of changes)over time. In terms of predicting meat quality, cumulative stress, ormore specifically cumulative energy expenditure, is more important thanacute stress (other than extreme acute stress). A cumulative measure ofskin/body temperature changes (both up and down) can provide an indexover time of the amount of energy spent by the animal. The more energyspent by the animal over a 24 hour period prior to its slaughter themore likely that the meat will be of poor quality if the animal is notallowed an additional period to replenish its energy stores via eating.

As stress has energetic consequences it can influence production returnand can have implications for animal welfare. A simple tool formeasuring and offering quality control on these would be useful.

Animals that have meat ultimate pH levels in an acceptable range (pH5.5-5.8) show a weak correlation between body temperature at slaughterand the actual meat pH. This correlation is greater if changes in bodytemperature are integrated over time, preferably for at least 12 hoursprior to slaughter. A convenient way to do this is to use a cumulativevariance around an averaged body temperature for an individual animal.Higher cumulative variances in temperature predict higher pH meat, ameasure that relates to the amount of glycogen residing in the meat.Based on the applicant's findings of the correlation between pH,temperature and stress, it is proposed that animal sensor devices may beproduced to monitor body temperature, and its variance, as a measure ofan animal's stress level and as a predictor of meat quality.

Animal temperature sensors are known in the art. For example, in U.S.Pat. No. 3,781,837 and U.S. Pat. No. 4,865,044, tympanic temperaturesensors are employed. In U.S. Pat. No. 4,854,328, a temperature sensordevice is implanted at the base of an animal's skull. An ear tagcomponent is provided which incorporates a unit for receiving signalsfrom the implanted sensor, and indicating means responsive to thegenerated signal. In the case of U.S. Pat. No. 4,865,044, an ear tag isemployed to contain the bulk of the temperature sensor circuitry, at aposition remote from the tympanic animal temperature sensor.

The use of tympanic and surgically implanted sensor devices is usuallycontraindicated because of the high invasive load on the animal.Further, dislodgement problems are also encountered with tympanicsensors. Where implanted devices are used, incisions can easily becomeinfected and the implantation procedure is more difficult to carry out.

Accordingly, it is a further object of at least a preferred embodimentof this invention to provide a temperature sensing device whichovercomes some of these disadvantages, or again at least provides thepublic with a useful choice.

In a first aspect, the present invention may be broadly said to consistin a method of providing an indication of pH levels in an animal, themethod comprising:

-   a) obtaining measurements corresponding to the body temperature of    the animal at periodic time intervals;-   b) applying an algorithm to the measurements obtained from a) which    algorithm cumulatively takes account of variations in body    temperature over time; and-   c) comparing the results of the algorithm to a predetermined    threshold or correlating the results of the algorithm with a pH    standard.

One simple algorithm is to calculate cumulative temperature variancewhich may be calculated in a number of ways. A simple method discussedin greater detail below comprises:

-   a) measuring the animal's body temperature at intervals over a    period of time;-   b) determining that animal's average body temperature reading over    that period of time;-   c) calculating the variance between each temperature measurements    taken under a) and the average determined in step b); and-   d) adding all variance values calculated according to step c) to    obtain the cumulative temperature variance score.

To calculate cumulative temperature variance at least two temperaturereadings must be taken. For accuracy, it is preferred that multiplereadings of 10 or more are taken in a predetermined time period.

From our discussions above, the reader will appreciate that the pH levelpredicted is an indicator of meat quality, with a pH level greater than5.8 indicating meat of poor quality.

In a further aspect, the present invention provides a method ofproviding an indication of stress levels in an animal, the methodcomprising:

-   a) obtaining measurements corresponding to the body temperature of    the animal at periodic time intervals;-   b) applying an algorithm to the measurements obtained from a) which    algorithm cumulatively takes account of variations in body    temperature over time; and-   c) comparing the results of the algorithm to a predetermined    threshold or correlating the results of the algorithm with a stress    standard.

In another aspect, the present invention provides a method of measuringstress levels in an animal, the method comprising measuring the animal'spH level using a method of the invention, a pH level greater than 5.8 to6.2 indicating a stressed animal.

In accordance with a further aspect of the present invention there isprovided a method of providing an indication of meat quality in ananimal, the method comprising:

-   a) obtaining measurements corresponding to the body temperature of    the animal at periodic time intervals;-   b) applying an algorithm to the measurements obtained from step a),    which algorithm cumulatively takes account of variations in body    temperature over time; and-   c) comparing the results of the algorithm to a predetermined    threshold or correlating the results of the algorithm with a meat    tenderness standard.

By way of example, the New Zealand lamb AC & A standard may be used as ameat tenderness standard. Outputs from the algorithm may bepre-calibrated to the standard so that in use, the result from thealgorithm may be compared with the standard to give an indication ofmeat tenderness.

In a specific form of the invention, the algorithm may calculate a meanof the measurements obtained in step (a); calculate a variance of eachmeasurement from the calculated mean; and integrate the variances overtime. In one preferred form of this embodiment, the measurements may betaken for a predetermined time period and a final mean calculated at theend of that predetermined time period. The integration of the varianceswill then be conducted over the predetermined time period. In analternative version of this simple algorithm based on variances from amean temperature, a running mean may be progressively determined fromthe measurements obtained in step (a). At each stage, the variation ofthe temperature measurement from the previous calculated running meanmay be integrated over time. This reduces the memory requirements of thedevice to implement the method.

More sophisticated algorithms may be employed which depart from thesimple method of calculating the variances from the mean. These moresophisticated algorithms may determine a cumulative value which isdependent on progressive changes or trends in the measurements obtainedfrom step (a), rather than being dependent on absolute temperaturemeasurements. This avoids the need to calibrate the temperature sensors.

Thus the measurements obtained from step (a) may or may not be actualtemperature measurements. For example, in any embodiment utilisingabsolute temperature values, relatively inexpensive thermistors may beemployed to obtain the temperature measurements with the circuitry inwhich the thermistors are employed compensating for any variation in themeasured temperature from the real temperature. This calibration may beeffected by calculating a correction coefficient and programming thisinto a microprocessor employed in the circuit.

In more sophisticated algorithms which rely on temperature changesrather than absolute values, no calibration may be required.

The body temperature is preferably measured on the outer part of theanimal since temperature adjustments to accommodate stress appear to bemore pronounced on the outer part of the animal compound to coretemperatures. In a most preferred form of the invention, the skinmeasurements may be taken e.g. on the ear of the animal.

In any embodiment in which the outer body temperature is determined onthe skin, a correction for the effects of ambient temperature will berequired. This can be achieved through the use of an ambient temperaturesensor. Additionally, correction for solar radiation may also berequired where the skin temperature sensor is exposed to sunlight. Thebody temperature may also be measured in more internal locations such asthe inner ear. This may avoid the requirement for ambient temperaturecompensation. However stress induced temperature fluctuation may be lessand more sensitive temperature measuring devices may be required whenmeasuring in this position.

In the simplest of embodiments where the algorithm is applied at the endof the predetermined time period, a device implementing the method maybe provided with an indicator to indicate the results of the comparisonstep conducted in step (c). If the failure of step (c) is indicated byway of a flashing light or audible alarm then the same facility may beused to periodically indicate the correct functioning of the device. Forexample, where a frequently flashing light indicates failure of step(c), an intermittent flashing of the same light may merely indicate thatthe device is functioning. A non flashing light will thus indicate to anattendant that the device has malfunctioned or has lost power.

In the embodiment where the algorithm is progressively employed to themeasurements obtained in step (a), step (c) may be employed after eachimplementation of the algorithm. Thus, if the animal fails the test atany point throughout a predetermined time period then an indicator maybe employed to show that the animal has failed the test. The method maythen be reemployed starting at the beginning of the predetermined timeperiod. If at any time during the retest the animal fails step (c) againthen the same indicator will indicate failure of the test and theprocess will be repeated. However, should the animal progress to the endof the predetermined time period without failing step (c) then analternative indication may be given that the animal has passed the testfor the full duration of the predetermined time period and thus is fitfor slaughter. Suitably once the animal has reached this point it shouldbe slaughtered without further delay and without the opportunity for theanimal to incur further stress.

In one specific implementation of the method, it may not be necessary towait for the full duration of a specific predetermined time period ifthe time period from rounding up to delivery of the animals to theabattoir is less than the predetermined time period. In the method whichprogressively applies the algorithm, if the animal has not yet failedthe test during the time thus far and if the conditions before thetesting started were such that the animals were unlikely to be subjectedto stress, then the animals might proceed to immediate slaughter.

In accordance with another aspect of the present invention, there isprovided a system for providing an indication of meat quality in ananimal to be slaughtered, the system including:

-   -   a body mountable measurement device for obtaining measurements        corresponding to the body temperature of the animal at periodic        time intervals over a period of 3-36 hours;    -   a processor having an input means to receive the measurements        from the measurement device, the processor operable to implement        an algorithm to the measurements, which algorithm cumulatively        takes account of variations in body temperature over time,        wherein the processor has an output means for the result of the        algorithm.

The system may be implemented in an all-in-one indicator device. Such adevice may be mounted on the animal eg ear tag, tail tag or provided ona collar. The tag may also incorporate the measurement device. In analternative form of the invention, the measurement device may be remotefrom the tag. The measurements may be sent to the processor by way of atransmitter or by a cable. In one preferred form of the invention, themeasurement device may be provided by way of a thermistor to bedeposited in the inner ear canal of the animal with a cable connected toan ear tag which houses the processor.

In yet another embodiment of the present invention, the processor may beprovided by way of a remote computer. In this embodiment, a device formounting on the animal will suitably incorporate transmitters to sendthe measurements to the remote computer. The remote computer may be afield device which is able to sense and account for ambient temperaturesand solar radiation. Alternatively, a separate field device may beprovided to send information relating to ambient temperature and solarradiation to a remote processor. The remote computer also receives themeasurements from the measurement device provided on the animal eitherdirectly or via the field device.

The output from the processor may be in any of various forms. A simplenumeric value may be output for the attendant to decide whether or notit falls within acceptable limits. The value might be compared to a meattenderness scale for quantitve assessment as to whether it falls withinacceptable limits. However, in most embodiments it is preferred that theprocessor is operable to compare the outputs of the algorithm to apredetermined threshold. The system may also include an indicator toindicate where the output of the algorithm has exceeded thepredetermined threshold. Any of the features described in connectionwith the above-described method of indicating meat quality may beimplemented in the system.

In accordance with yet another aspect of the present invention, there isprovided a system for indicating cumulative stress in an animal, thesystem including:

-   -   a body mountable measurement device for obtaining measurements        corresponding to outer body temperature of the animal at        periodic time intervals over a period of 3-36 hours:    -   a processor having an input to receive measurements from the        measurement device, the processor operable to implement an        algorithm to the measurements, which algorithm cumulatively        takes account of variations in body temperature over time,        wherein the processor has an output for the result of the        algorithm.

The system for providing an indication of stress may be implemented inany of the various forms discussed above for the system providing anindication of meat quality. Such a system for indicating cumulativestress might have particular application to animals where the effects ofstress might be dangerous either to the animal itself, to other animalsor in particular to humans. For example, horses might be more prone toerratic behaviour and a danger to their riders if they are subjected tosustained periods of stress. A system implemented in the form of anall-in-one indicator device may provide simple indication to the riderthat the animal is stressed and needing rest or food.

Preferably, the processor is also operable to compare the output of theprocessor with a predetermined threshold. The system preferablyincorporates an indicator to provide indication that the predeterminedthreshold has been exceeded. In an all-in-one indicator device, this maybe implemented by a simple visual indicator such as a flashing led. Inan embodiment with a remote computer then the output of the computer mayprovide the identification numbers of those animals which have exceededthe threshold.

In accordance with a still further aspect of the invention, there isprovided a system of providing an indication of ultimate meat pH of ananimal, the system including:

-   -   a body mountable measurement device for obtaining measurements        corresponding to outer body temperature of the animal at        periodic time intervals over a period of 3-36 hours:    -   a processor having an input to receive measurements from the        measurement device, the processor operable to implement an        algorithm to the measurements, which algorithm cumulatively        takes account of variations in body temperature over time,        wherein the processor has an output for the result of the        algorithm.

In a further aspect, the present invention provides:

A temperature sensing device including:

-   -   a tag having an attachment portion to extend through a body part        of an animal, the tag incorporating an indicator means; and    -   one or more animal temperature sensors disposed on/in the        attachment portion for contact with the animal during use.

Preferably, the tag is an ear tag. Preferably, an ambient temperaturesensor is also provided 100 on the tag. Further, the tag may be providedwith comparison means to compare the ambient temperature with the animaltemperature. An indicator may also be disposed on the tag, the indicatorbeing responsive to the comparison means.

Desirably, the tag comprises a one piece moulded body.

Also contemplated by the present invention is the use of the temperaturesensing device in the methods of the invention as described above.

This invention may also be said broadly to consist in the parts,elements and features referred to or indicated in the specification ofthe application, individually or collectively, and any or allcombinations of any two or more of said parts, elements or features, andwhere specific integers are mentioned herein which have knownequivalents in the art to which this invention relates, such knownequivalents are deemed to be incorporated herein as if individually setforth.

The invention consists in the foregoing and also envisages constructionsof which the following give examples.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to theaccompanying drawings in which:

FIG. 1 is a diagrammatic view of an embodiment of a temperature sensingdevice of the present invention from the inward facing or “animal” side.

FIG. 2 is a side view of a temperature sensing device of the presentinvention.

FIG. 3 is a diagrammatic view of an embodiment of a temperature sensingdevice of the present invention from the outward facing or “environment”side.

FIG. 4 is a graph plotting the ultimate pH of meat with temperaturevariance from Example 1.

FIG. 5 is a graph plotting the results of Example 2, correlatingvariance in skin temperature around a mean value over 24 hours in sheepwith ultimate pH.

FIG. 6 is a graph plotting the results of Example 3 showing the mean andSD rectal temperatures of adult sheep with similar levels of infectiontaken at the same time each day at the same ambient temperature. The earskin temperatures are plotted against corresponding the rectaltemperatures.

FIG. 7 is a circuit diagram of a circuit which may be implemented in atemperature sensing device which is slightly modified from the deviceshown in FIGS. 1 to 3.

FIG. 8 is a graph plotting temperature readings and the output of apreferred algorithm in accordance with a preferred embodiment of thepresent invention.

DETAILED DESCRIPTION

As summarised above, the present invention is based upon the applicant'sunexpected finding of the correlation between stress, body temperatureand variance over time of body temperature, pH and ultimately meatquality in livestock. This finding has important consequences for theagriculture industry generally and the primary meat industry inparticular. By identifying stressed animals prior to slaughter,appropriate management techniques can be used to reduce the animals'stress level. This will ensure a higher quality meat product afterslaughter.

The applicant's findings also have broader application to methods ofpredicting or measuring pH levels based on the pH/temperaturecorrelation.

Animal body temperature may be measured using a broad range oftemperature sensors including tympanic, rectal, colonic, and skinsensors. Sensors ingested or inserted in bodily canals are not widelyused due to the difficulty of inserting them, and because they areeasily dislodged or expelled by an animal. Preferably, a skintemperature measurement is taken to avoid these invasive and lessdesirable alternative techniques. Conveniently, temperature may bemeasured using a temperature sensing device of the present inventiondiscussed below. However, with temperature measurements from the skin asopposed to the body core, the ambient environmental temperature must betaken into account. The slope of prediction between variance intemperature and ultimate pH of meat shows consistency with temperaturechange. However, it shifts to the right, or to the left, depending uponthe environmental conditions including temperature and solar radiation.

Measures of animal and ambient air temperature or measurementscorresponding thereto, and usefully over a predetermined time period arerequired. On the farm, any time interval, regular or irregular, desiredmay be selected. Continual on-line monitoring not limited to a specifictime period is contemplated. Alternatively, monitoring for selected timeperiods of hours, days, weeks or even months is feasible.

In the slaughtering context, the correlation between body temperature atslaughter and pH levels of meat are stronger if the measures areintegrated for an extended period, which may be up to 2-5 days, but ispreferably between 3-36 hrs, more preferably 8-24 hrs and mostpreferably at least 12-14 hours prior to slaughter.

Within the monitoring period it is preferred that measurements be takenat regular intervals such as hourly, half hourly, every quarter hour,every ten minutes or the like. The preferred regime is no more frequentthan every ten minutes.

The applicants have found that skin/body temperature may reflectmetabolic activities associated with the stress response. A greaterstress response is likely to result in a greater metabolic activation tore-establish the homeostatic norm either through a greater generation ofheat and elevation of body temperature or heat loss and a lowering ofbody temperature. Except in circumstances of pathophysiological heatexhaustion, dehydration or febrile responses these changes are usuallyshort-lived in nature and small in magnitude.

Measurements of animal body-temperature made at discrete points of timeduring the pre-slaughter period are unlikely to give a representation ofthe stress experienced cumulatively over the preslaughter period. Asingle experienced stressor is unlikely to cause meat quality problemswhereas cumulative stressor exposure over a period of time, withoutreplenishment, will do so.

Correspondingly, single point temperature measures may well coincidewith either a single stressor induced peak or a trough between numerousstressor induced peaks in body temperature, either way unlikely toprovide an accurate assessment. It is for this reason that measurementsover a time period prior to slaughter are required.

The applicant hypothesised that the best measure of energy used, and bycorrespondence glycogen depleted from muscles and predicted ultimate pH,would be the variation in body (or skin) temperature over time. Thevariation will represent both periods in which skin/body temperature hasfallen and the required energy consumption to correct, and periods inwhich body temperature has risen, reflecting increased metabolism andits energy consumption and necessitating heat loss.

A measure of the temperature variation (variance) can be calculated innumerous ways. However, a simple cumulative measure using single measuresample period repeated over the required time is as follows:

-   -   find the arithmetic average (x) of all the pooled samples (y1, .        . . yn) where I=the first sample variable y and n the last in        the sequence, which is also the total number of samples.        x=sum(y1+y2+ . . . y_(n))/n    -   measure and record the variance (v1, . . . vn) of each sample        (y1 . . . yn) from this average (x) (i.e. the difference between        each sample and the average). Irrespective of whether each        sample point is less or more than the average the difference        will be indicated as a positive number. v1=x−y1, . . . vn=x−yn.

A further weighting may to be given to each variance dependent uponwhether it is above or below the average. Values above the average ormean have energy associated both with generation (variance) and theenergy loss through heat transfer needed to return to the average. Assuch their variance weighting should be greater than those below theaverage that utilises energy only in returning to the average baseline.

These numbers are then cumulatively added to give a variance score overa predetermined time period. This time period will usually need to be 12hours or greater to provide meaningful interpretation as to glycogendepletion and energy usage as discussed above. vc=Sum(v1+v2+ . . . vn)

The greater the cumulative score, the greater the energy usage that hasoccurred and correspondingly the greater the likelihood of both glycogendepletion and subsequent post-slaughter poor meat quality.

To calculate the prediction of meat quality a weighting should also begiven to the variance depending upon the environmental conditions.Increasing ambient temperatures are associated with a subtractiveweighting, decreasing ambient temperatures with an additive weighting.Solar radiation can also be accommodated for using this method.

The weighting for ambient temperature is approximately ±0.2 pH unit per3° C. above and below 20° C. (standard weighting of zero).

Based on the applicant's determination of a correlation betweentemperature and pH, the cumulative effects of variation in bodytemperature can be manually or electronically correlated with ultimatemeat pH using a standard. For example, standardised against a MettlerToledo pH meter and standards (Mettler Toledo GmbH, Steinbach). Furtherit could be correlated to any other measure of hydrogen ionconcentration, typically using a glass electrode, but other methodsincluding ion selective field effect transistor electrodes could beused. As the increasing pH in meat is correlated with an increase inlactate, a measure of lactate also provides suitable correlation.

The pH level measured can be used as an indicator of an animal's stresslevel, a pH of greater than 5.8 indicating stress.

Where an animal is found to be stressed, remedial action to lower stresslevels can be taken prior to slaughter. A period of feeding shouldalleviate stress by replenishing glycogen in muscle tissue. This actionhelps prevent or eliminate post-slaughter meat quality problems.

The methods of the invention may be used in relation to a broad range ofanimals including domesticated livestock such as sheep, cattle, deer,pigs, chickens, turkeys, ducks, emus, ostriches, rodents, chinchillasand additionally rabbits, possums, goats and the like, as well as theferal counterparts of all of these. Preferred livestock for analysis aresheep, cattle, deer and pigs.

As noted above, the present invention also provides a temperaturesensing device depicted generally by the numeral “10” in theaccompanying figures. The sensing device (10) is useful in the methodsof the invention for measuring temperature. A sensing device (10) of theinvention includes a tag represented by the numeral “12”. The tag (12)may comprise any of the tags known in the art which can be attached tothe skin of an animal, including through the skin, folds thereof, ortissues. Examples of useful tags include ear tags, back tags and tailtags.

Ear tags are conveniently employed.

Two part ear tags are disclosed in U.S. Pat. No. 4,854,320 or three parttags of the type disclosed in U.S. Pat. No. 5,675,920 may be used. Onepart tags wherein an attachment portion of the tag passes over the topof, and back through the ear and tag are also feasible. Currentlypreferred is a two part tag as illustrated in FIG. 2. For example, theTru-Test7 perma-flex ear tag (Tru-Test Limited, 241 Ti Rakau Drive, EastTamaki, Auckland, New Zealand). The tags are generally useful fordomestic livestock such as sheep, cattle, deer and goats but are notlimited thereto.

The tag (12) incorporates at least one attachment portion (14). Theattachment portion (14) comprises any suitable attachment means known inthe art including any form of skin piercing. The attachment portion (14)may be selected according to the position of attachment on the animal.Suitable attachment portions may include shafts, bands, hooks insertableinto or through selected animal tissues, or attachment portionsadherable thereto. For example, tags could be superglued to the skin ofan animal at a desired location. Preferably, the attachment portion (14)includes a shaft (17) insertable through the ear of an animal. Wherenecessary backing member(s) (15) may be used to securely fasten the tagto the ear of the animal. The backing member (15) may include a furthertag body in some cases. Alternatively, in one embodiment discussedabove, the attachment portion (14) may be secured back to the tag (12).

The tag (12) incorporates at least one animal temperature sensor (20)disposed on or in the tag. The sensor (20) is disposed at any locationon or in the tag (12) which ensures contact of the sensor (20) with theanimal during use. In one embodiment the sensor (20) is in the vicinityof the attachment portion (14). In a preferred embodiment shown in FIG.2, the sensor (20) is provided on or in the shaft (17) of the attachmentportion (14). The location of the sensor (20) in the shaft (17) ensuresclose contact of the sensor with the animal ear.

The temperature sensor (20) itself may comprise any suitable sensingmeans known in the art including electronic sensors or thermistors.Temperature sensors suitable for use in the invention are disclosed inU.S. Pat. No. 4,854,328 and U.S. Pat. No. 4,865,044 at least.

As discussed above, where outer body temperature readings, such as skintemperature are used, then the ambient environmental temperature shouldalso be measured. For example, on a hot day an animal's body temperaturewill rise. If not correlated with air temperature this would falselyindicate a stressed or sick animal. Logically therefore, a more accurateassessment of an animal's body temperature can be made if the ambientair temperature is taken into account.

Accordingly, while a tag (12) without an ambient temperature sensor iscontemplated, the tag (12) preferably further includes at least oneambient temperature sensing means (18) provided on the tag (12) at anyposition suitable for measuring ambient air temperature. Most usually,the ambient temperature sensor (18) will be disposed on or in the sideof the tag (12) away from the animal, as shown in FIG. 1. Temperaturesensors of the type used for animal temperature measurement may also beemployed for ambient temperature measurement. Such other air temperaturesensors as are known in the art may also be used.

Correlation of both body and air temperature data can be performedmanually by an observer. However, it is preferred that the sensingdevice (10) further include comparison means for correlating temperaturedata from both the air and body temperature sensors (18 and 20).Usually, the comparison means will be a microprocessor (22) butapplication specific electronics could also be implemented.

In order to resolve difficulties associated with heating of the ear tagdue to solar radiation, the animal temperature sensor could instead belocated some distance from the tag. This is easily done by positioningthe body of the tag just inside the ear flap and the sensor just insidethe ear canal. The sensor can be located on the end of a flexible wireand glued to the ear. Ambient temperature effects can be minimised bycovering the sensor with a small dot of foam insulating tape.

The data output of the body and/or temperature sensor means (18 and 20)may also or alternatively, be sent to remote evaluation means. This willgenerally require the coupling of the sensor means (18 and 20) to atransmitter. Temperature data as well as animal identification data istransmitted to a remote processor such as a computer. In the case oftagged animals this will permit remote monitoring and checking to beperformed, continuously if desired.

In the presently preferred embodiment, the temperature informationgathered by both sensors (18 and 20) is relayed to microprocessor (22).In this regard, refer to FIG. 7 which illustrates the circuit diagramfor a device according to a slightly modified embodiment. While changeswould be required to implement this circuit in the present embodimentthe principles of operation are the same. Reference is also made to U.S.Pat. No. 4,854,328, U.S. Pat. No. 4,865,044 and U.S. Pat. No. 3,781,837which disclose circuitry which could be adapted for this use.

The microprocessor (22) is in turn in responsive communication withindicator means (16). The indicator means (16) may be selected from abroad range of currently known indicators including electronic, visualand acoustic signal generators but are not limited thereto.

In the case of an electronic indicator this may be a device programmedto give out a perceivable signal once a certain predeterminedtemperature is reached.

In one embodiment, the indicator means (16) may comprise a temperatureresponsive substance which generates a visual, electromagnetic,electrochemical, or other measurable signal when a predeterminedtemperature is exceeded. Visual changes such as a change in colour areconveniently employed. Colour change indicators will generally comprisea substance which undergoes a change in state at a precise andpredetermined temperature.

In a further embodiment, the indicator means (16) may comprise aplurality of regions, generally less than 10 and preferably less than 5,which undergo a change of state at precise, graduated predeterminedtemperatures. When colour changes are employed this may usefully resultin the graduated change in colour of the indicator from a small portionto substantially the entire indicator. In an embodiment whichprogressively applies the algorithm resulting in a progressivelyincreasing cumulative value, this progressive colour change mighteffectively indicate the progressively increasing cumulative value.Alternatively, the colour change might be simply representative ofincreasing animal temperature. Alternatives include a “traffic light”indicator which, for example, changes from green, to amber, and finallyto red as the threshold is exceeded. Other possibilities include opaquematerials becoming transparent or translucent to reveal underlyingcolours as the cumulative value increases or the temperature changes.

The indicators may undergo irreversible changes, especially whencontinuous monitoring is not contemplated.

Further visual indicator means (16) include, for example, LEDs orflashing lights. Alternatively, audible alarms may be triggered.Combinations of all such indicator means are also feasible. Alsocontemplated are outputs readable at remote locations. A wide range ofindicator means (16) which may be employed in the invention aredisclosed in the following US patents: U.S. Pat. No. 3,781,837, U.S.Pat. No. 4,865,044, U.S. Pat. No. 4,854,328 and U.S. Pat. No. 5,675,920amongst others.

Depending on the types of sensors, indicator and comparison meansemployed, the sensor device may require a power source. While solarpowered devices are contemplated, at least one battery will usually beincorporated into the sensing device (10). In the preferred embodimentdepicted in FIG. 1, a battery “24” is employed. A wide variety ofbatteries (24) are currently available and suitable for use in the eartag (12).

Where batteries (24) are employed as a power source it is important toidentify when a battery (24) has malfunctioned or expired. An indicatorshowing when the power source has failed would therefore be useful. Anappropriate indicator is identified by the numeral “26” in FIG. 1. Aswith the sensing means, useful indicators include electronic, audio andvisual signals as discussed above. For example, when the battery hasfailed an audible signal could be emitted, driven by a small backuppower source. Preferably however, the signal is a visual colour changesignal, or extinction of an “OK” LED signal. The colour change may besignalled as an alternative to the temperature colour change signal, orin addition to it provided that the colour changes are distinctive.

The tag (12) may further incorporate communication means. Thecommunication may comprise the export of data and/or for the import ofenergy. Accordingly, uni- and bi-directional communication means arecontemplated. Suitable communication means are identified in the USpatents referenced above. They include at least one transmitter and/orantenna but are not limited thereto. In a preferred embodiment of thepresent invention an antenna (28) is included in the tag (12). Theantenna (28) preferably allows bi-directional data communication withthe tag (12).

In one use, the antenna (28) provides a means of recharging the battery(24) by use of electromagnetic radiation or an externally applied radiofrequency field. In a further use, the antenna (28) permits export ofdata for logging purposes. Communication may be to remote data loggingmeans to facilitate off-site monitoring of animals. Exported datasignals may also provide information relating to the identificationnumber of the animal.

It is also customary for tags (12) to include animal identificationmeans. In a simple form this may comprise a unique visual identificationmeans such as a symbol, colour or pattern. Preferably, the visual IDcomprises an alphamerical number (30) as shown in FIG. 3. Alternateidentification means include electronic identifications, orelectronically readable signals which uniquely identify a given animal.Any such electronic signals which are known in the art may be used. Oneembodiment preferred is the inclusion of a barcode (32) on the tag (12)as shown in FIG. 3. This facilitates scanning of the tag (12) andcorrelation of data with pre-existing information for the uniquelyidentified animal. Specific identification systems can also assist indiscouraging theft of stock.

The electronic componentry of the ear tag (12) comprising any of all ofthe antenna (28), battery (24), battery indicator (26) andmicroprocessor (22) may be provided on or in the tag (12) convenientlyon a circuit board (34). Preferably, the componentry is provided withinthe tag (12) to prevent damage. This may be achieved by covering thecomponentry once fixed on the tag (12). The cover may be permanentlyfixed in place or can be releasable. A releasable cover would allow forbattery replacement. If the cover is fixed, this may be achieved bygluing, plastic welding or other known fastening means.

Conveniently, the tag (12) is a one piece moulded body.

In a preferred form the tag (12) comprises an integrally moulded bodywith the componentry sealed therein.

In use, the temperature sensors (18 and 20) of the ear tag (12) willcollect temperature data which is communicated to the microprocessor(22) to perform the necessary cumulative algorithms discussed above.

If the outcome of the calculation is a temperature threshold value thatindicates a pH of poor quality (greater than 6.2) then a power surge isdirected to the indicator to cause an electronic, visual or audiblechange. The livestock owner or manager can then take steps to reduce thestress level in the animal through appropriate feeding regimes.

High temperature readings may also indicate infected or otherwiseunhealthy animals. For pathophysiological measurement either a spike orchronic rise in body temperature can be an important diagnostic tool ofdisease while longer term tracking can show whether therapeutictreatment of the disease is effective. The tags can therefore serve thedual purpose of signalling the state of health of the animal apart fromstress responses. In related applications, the tags can be used inmonitoring the status of other processes in animals which at some pointare characterised by temperature changes. An example of this ismeasurement of hormone changes or cycles such as oestrous in an animal.

The useable lifetime of the tag is approximately one month. The lifespanof the tag can be extended through the incorporation of a battery (24)able to be recharged by electromagnetic radiation or radio frequency inthe field. Accordingly, both disposable single measure tags (12) andreusable tags (12) are contemplated herein. Disposable tags (12) may beparticularly appropriate for short term use in the pre-slaughter period.Custom electronics could greatly increase this lifetime. Once tagidentification of a problem occurred, an electronic ID associated withthe tag could activate automatic drafting of the animal from a group forremedial action.

FIG. 7 is a circuit diagram of a circuit (40) appropriate for use in atag such as that illustrated in FIGS. 1 to 3, except without the antenna(28).

At the heart of the circuit is microprocessor 42) which receives imputsfrom ear temperature sensor TH2 and ambient temperature sensor TH1. Themicroprocessor (42) implements an algorithm which cumulatively takesaccount of temperature variations in an animal over time. Simplealgorithms integrating variations from a mean body temperature over timehave been described above. Also described below is a more sophisticatedalgorithm which may be implemented by microprocessor (42). As anadditional input to the microprocessor (42), there is provided a clock(44) which controls the sampling interval at which the microprocessor(42) receives temperature readings from thermisters TH1 and TH2.

The circuit (40) is driven by battery (46) which provides power to thecircuit for up to six weeks. A lamp 48 such as LED D1 may flash atintermittent intervals, say every 5 to 10 seconds, to indicate that thecircuit is operating. The LED D1 may also be used to provide anindication when the output of the algorithm is such as to exceed apredetermined threshold. In that case, the LED may flash frequently, sayevery 1 second. This will attract the attendant's attention so that thestressed animals will not be put to immediate slaughter but insteadrested and revived as required.

The circuit (40) also includes an optional memory unit (50) which canstore up to 4,000 temperature measurements. This will be implemented ifthe tag is to be used as a diagnostic tool. The data stored in thememory unit (50) may be uploaded via the optional interface (52).

A more sophisticated algorithm for obtaining a cumulative measure oftemperature variations in an animal will now be described.

Variable Definitions:

-   -   Let t_(ear) be the instantaneous ear temperature    -   Let t_(ambient) be the instantaneous ambient air temperature    -   d is the difference between ear and ambient temperatures    -   fast is the fast-response filter element    -   slow is the slow response filter element    -   v is the integral of the difference between the two filter        elements    -   c₁ is the time constant of the fast filter. The time constants        are selected according to sampling interval time and threshold        detection level.    -   c₂ is the time constant of the slow filter    -   Time constants are such that c₁>c₂, 0<c₁<1, 0>c₂<1    -   n is the count for the sampling time interval        Initialise:    -   n=1    -   d₀=t_(ear)−t_(ambient)    -   fast₀=d₀    -   slow₀=d₀    -   V₀=0        At each sampling time interval:    -   d_(n)=t_(ear)−t_(ambient)    -   fast_(n)=(1−c₁)*fast_(n−1)+c₁*d_(n)    -   slow_(n)=(1−c₂)*slow_(n−1)+c₂*d_(n)    -   V_(n)=V_(n)+(fast_(n)−slow_(n))

The microprocessor is programmed to repeat the algorithm regularly ateach sampling interval until a predetermined time period has elapsed. Ifat any time during this predetermined time period v_(n) exceeds apredetermined threshold then the animal is taken to be stressed and lamp(48) of circuit (40) will flash frequently to provide appropriateindication to the attendant. The timer will reset and remain at 0 untilv falls below the threshold, at which point the timer will startcounting for a predetermined animal withholding period, the timer willagain be set to zero. In this way it is ensured that the animaleffectively recovers from stress, prior to slaughter.

If, at the elapse of the predetermined time period v_(n) is less thanthe threshold then the animal is taken to be within acceptablecumulative stress limits. The lamp (48) may provide an indication thatthe threshold has not been exceeded.

In the above described algorithm, the entire history of temperaturereadings is not required, only the most recent reading. Thus, thealgorithm requires only three storage locations to be preserved betweentime steps.

The use of the filter elements removes any dependence on absolutereference temperatures and the need to calibrate the temperaturesensors. The filter elements detect trends rather than absolutetemperature values.

The filter elements are more resistant to the effects of measurementnoise than simple threshold detection.

FIG. 8 illustrates an example for the particular algorithm describedabove. Note that the threshold detection is immune to base line shiftsor small spikes in the data. Instead, a long consistent temperature riseis required for detection. The algorithm thus effectively models therise in body temperature due to stress.

Non-limiting examples illustrating the invention will now be provided.

EXAMPLE 1

Data were obtained in the following manner:

Three groups of twenty prime bulls (18 months of age) were exposed toperiods of stressful handling during a 24 hour period lead up period toslaughter.

During this time skin temperature from the ear of each individualanimals was measured every 10 minutes. From this an average wascalculated and the cumulative variance measured by adding eachindividual measure difference from the average.

Cumulative variances were then plotted against individual ultimate pHvalues obtained post-slaughter from meat. Variance values against a setultimate pH value are presented as an average and standard deviation.

Each group of animals was exposed to a different controlled ambienttemperature of 16, 20 or 24 degrees Celsius for the trial period.

In each case the correlation coefficient r² was greater than 0.90 forvariance in temperature predicting ultimate pH of meat.

FIG. 4 presents data for the relationship between variance intemperature and ultimate pH of the meat. Note that below a pH of 6.0 noclear relationship exists. As depicted, variance in body temperaturepredicts only a pH above 6.0.

For ultimate pH prediction an equation can be calculated to provide analgorithm combining the cumulated variance and the environmenttemperature.

EXAMPLE 2

20 Adult sheep were subjected to various stressors including roundingup, lairage and transport in the 24 hours prior to slaughter. Ear skinmeasurements were made during this time, every 15 minutes. For eachanimal, measurements were averaged over the 24 hours and then for eachmeasured point a variance from mean score was given using degreescelsius above or below the mean.

The greatest total individual variance was ranked numerically as 10 andthe others normalised as a dividend of this. These variances were thencorrelated with the ultimate pH obtained from the meat of theslaughtered animals. The results are shown in FIG. 5 which showsrelationship of variance in skin temperature around a mean value over 24hours in sheep correlated against their ultimate pH. The correlationcoefficient is displayed. This data suggests that in sheep, as forcattle, measurement of variation in skin or body temperature over aperiod prior to slaughter can predict the ultimate meat quality.

EXAMPLE 3

A group (14) of adult sheep being monitored developed respiratory andparasitic infections. Monitored ear skin temperatures showed goodcorrelation (correlation coefficient of 0.81) with rectal temperaturesin terms of fever peaks and return to normal body temperatures withtreatment.

The data plotted in FIG. 6 supports the notion that ear skin or earcanal temperature can be used to measure pathophysiological states thathave accompanying febrile symptoms and recovery from these states.

It will be appreciated that the above description is provided by way ofexample only and that variations in both the materials and techniquesused which are known to those persons skilled in the art arecontemplated.

REFERENCES

-   ¹ Cook, C. J. and Devine C. E. (1990) From farm paddock to slaughter    floor: a conundrum of biochemical and physiological effects that    influence meat quality. AGMARDT Beef Industry Research Development    Conference. NZMPB.-   ² Purchas, R. W. (1990) An assessment of the role of pH differences    in determining the relative tenderness of meat from bulls and    steers. Meat Sciences 27, 129-140.-   ³ Watanabe, A., Daly, C. C. and Devine C. E. (1995) The effects of    ultimate pH of meat on the tenderness changes during ageing. Meat    Science 42, 67-78.-   ⁴ Jacobson, L. H. and Cook, C. J. (1997) The effect of pre-transport    cattle management on stress, metabolism and carcass weight of bulls.    In: Proceedings of the 43rd International Congress on Meat Science    and Technology. Auckland, NZ, pp302-303.-   ⁵ Jacobson, L. H., Cook, C. J., Hodgetts, B. V. and Dean, J. M. The    effect of pre-transport on on-farm holding and supplementary    feeding, on welfare and meat characteristics of bulls subsequently    transported for slaughter. September 1997. (Funding Milestone,    MRDC).-   ^(A) Devine C. E. and Chrystall, B. B, (1992) Meat Science, in    encyclopedia of Food Science and Technology, ed Hui, Y. H.,    WileyInterscience, John Wiley and Sons, Inc., New York 17081723.-   ^(B) Devine C. E. and Chrystall, B. B. (1989) High ultimate pH in    sheep in Darkcuttinu in cattle and sheep. Proceedings of an    Australian Workshop. Pp 5565 Ed. S. U.

Fabiansson, W. R. Shorthose and R. D. Warner AMLRDC, Sydney Australia.

-   ^(C) Devine C. D. Graafhuis, A. E. Muir, P. D. and    Chrystall, B. B. (1994) The effect of growth rate and ultimate pH on    meat quality of lambs. Meat Sci. 36 143-150

All US references cited in the text of this specification areincorporated herein by reference.

1. A method of providing an indication of at least one of meat quality,pH levels, and stress levels in an animal, the method comprising:obtaining measurements corresponding to a body temperature of the animalat periodic sampling intervals over a predetermined time period;determining an indicator or measure of the sum total extent of all ofthe variation in said measurements over said time period; and comparingsaid indicator or measure of the sum total extent of all of thevariation to a predetermined threshold to determine the indication. 2.The method as claimed in claim 1 wherein ten or more measurementscorresponding to body temperature are taken.
 3. The method as claimed inclaim 1 wherein the predetermined time period is at least 12 hours. 4.The method as claimed in claim 1 wherein the predetermined time periodextends up to 24 hours.
 5. The method as claimed in claim 1 wherein theindication or measure of the extent of variation algorithm is applied ata end of the predetermined time period.
 6. The method as claimed inclaim 1 wherein the indication or measure of the extend of variation isapplied progressively.
 7. The method as claimed in claim 6 wherein saidcomparing is conducted after each application of the algorithm.
 8. Themethod as claimed in claim 6 wherein the indication or measure of theextent of variation is applied progressively as each measurementcorresponding to body temperature is taken.
 9. The method as claimed inclaim 1 further comprising, in the event of the threshold beingexceeded, providing an indication of the threshold being exceeded. 10.The method as claimed in claim 9 further including setting the animalaside for a predetermined animal withholding period in the event of thethreshold being exceeded.
 11. The method as claimed in claim 1 whereinthe determining said indication or measure of the extent of variationcomprises: where: t_(ear) is the instantaneous ear temperature;t_(ambient) is the instantaneous ambient air temperature; d is thedifference between ear and ambient temperatures; fast is thefast-response filter element; slow is the slow response filter element;v is the integral of the difference between the two filter elements; c₁is the time constant of the fast filter; c₂ is the time constant of theslow filter; Time constants are such that C₁>c₂, 0<c₁<1,0<c_(2<1;) whereinitially: n=1 d₀=t_(ear)−t_(ambient) fast₀=d₀ slow₀=d₀ v₀=0  and whereat each sampling interval: d_(n)=t_(ear)−t_(ambient)fast_(n)=(1−c₁)*fast_(n−1)+c₁*d_(n) slow_(n)=(1−c₂)*slow_(n−1)+c₂*d_(n) then: v_(n)=V_(n−1)+(fast_(n)−slow_(n)).
 12. The method as claimed inclaim 1 wherein the measurements are taken on the outer part of theanimal's body.
 13. The method as claimed in claim 12 wherein skintemperature measurements are taken and compensation is provided for atleast ambient temperature or solar radiation.
 14. The method as claimedin claim 12 wherein measurements are taken in the ear canal of theanimal.
 15. A method of providing an indication of at least one of meatquality, pH levels, and stress levels in an animal, the methodcomprising: a) obtaining measurements corresponding to a bodytemperature of the animal at periodic sampling intervals; b) applying analgorithm to the measurements obtained from a), which algorithmcumulatively takes account of variations in body temperature over time;and c) correlating the results of the algorithm with at least one of ameat tenderness, a pH, and a stress standard.
 16. The method as claimedin claim 15 wherein a mean is calculated progressively as eachmeasurement corresponding to temperature is taken.
 17. A system forproviding an indication of at least one of meat quality, pH levels, andstress levels in an animal to be slaughtered, the system comprising: abody mountable measurement device for obtaining measurementscorresponding to the body temperature of the animal at periodic samplingintervals over a period of between 3-36 hours; and a processor orcontroller configured to: receive said measurements from saidmeasurement device; determine an indicator or measure of the sum totalextent of all of the variation in said measurements over said period;compare said indicator or measure of the sum total extent of all of thevariation to a predetermined threshold to obtain a result; and providingsaid result of said comparison as output.
 18. The system as claimed inclaim 17 wherein said processor further configured to: determine theanimal's mean body temperature from the measurements; calculate thevariance between each measurement and the mean; and add all variances toobtain a cumulative variance score.
 19. The system as claimed in claim17 wherein the algorithm comprises the following the indication ormeasure of the extent of variation is determined: where: t_(ear) is theinstantaneous ear temperature; t_(ambient) is the instantaneous ambientair temperature; d is the difference between ear and ambienttemperatures; fast is the fast-response filter element; slow is the slowresponse filter element; v is the integral of the difference between thetwo filter elements; c₁ is the time constant of the fast filter; c₂ isthe time constant of the slow filter; Time constants are such thatC₁>c₂, 0<c₁<1,0<c₂<1; where initially: n=1 d₀=t_(ear)−t_(ambient)_(fast0)=d₀ _(slow0)=d₀ V₀=0 and where at each sampling interval:d_(n)=t_(ear)−t_(ambient) fast_(n)=(1−c₁)*fast_(n−1)+c₁*d_(n)slow_(n)=(1−c₂)*slow_(n−1)+c₂*d_(n) then:v_(n)=v_(n−1)+(fast_(n)−slow_(n)).
 20. The system as claimed in claim 17wherein the system: is embodied in an all-in-one indicator device. 21.The system as claimed in claim 20 wherein the device is provided in theform of an ear tag.
 22. The system as claimed in claim 21 wherein thetag incorporates the measurement device.
 23. The system as claimed inclaim 17 wherein the processor is provided by way of a remote computer.24. The system as claimed in claim 17 wherein the processor is adaptedto output a numeric value from a comparison with a meat tendernessscale.
 25. The system as claimed in claim 17 wherein the processor isoperable to compare the output of the algorithm to a predeterminedthreshold.
 26. The system as claimed in claim 25 further including anindicator to indicate where the output of the algorithm has exceeded thepredetermined threshold.
 27. The system as claimed in claim 26 whereinthe indicator is also operable to provide an indication that the systemis functioning.
 28. A temperature sensing device comprising: a taghaving an attachment portion to extend through a body part of an animal;one or more animal temperature sensors disposed on/in the attachmentportion for contact with the animal during use and providing an outputindicative of temperature; and an indicator mounted on the tag orincorporated therewith and communicating with the one or more animaltemperature sensors, said indicator being configured to provide a localindication depending on said output from said one or more animaltemperature sensors.
 29. The tag as claimed in claim 28 wherein the tagis an ear tag.
 30. The tag as claimed in claim 28 wherein an ambienttemperature sensor is also provided on the tag.
 31. The tag as claimedin claim 28 wherein comparison means is provided for comparing theambient temperature with the animal temperature.
 32. The tag as claimedin claim 31 wherein the indicator is disposed on the tag, the indicatorbeing responsive to the comparison means.
 33. The tag as claimed inclaim 28 wherein the tag comprises a one piece molded body.
 34. A methodof providing an indication of at least one of meat quality, pH levels,and stress levels in an animal, the method comprising: obtainingmeasurements corresponding to the body temperature of the animal atperiodic sampling intervals; determining that animal’ mean bodytemperature reading over the predetermined time period; calculating thevariance between each measurement and the mean determined; and addingall variances to obtain a cumulative temperature variance score,comparing said score to a predetermined threshold.
 35. The method asclaimed in claim 34 wherein the variance is calculated progressively.36. The method as claimed in claim 35 wherein the variance is calculatedprogressively as each measurement corresponding to body temperature istaken.
 37. The method as claimed in claim 35 wherein the comparison isconducted after each application of the algorithm.
 38. A method ofproviding an indication of at least one of meat quality, pH levels, andstress levels in an animal, the method comprising: obtainingmeasurements corresponding to the body temperature of the animal atperiodic sampling intervals; calculating progressively a mean as eachmeasurement corresponding to temperature is taken; applying an algorithmto the measurements which cumulatively takes account of variations inbody temperature over time; and comparing the results of said algorithmto a predetermined threshold.
 39. A method of providing an indication ofat least one of meat quality, pH levels, and stress levels in an animal,the method comprising: obtaining measurements corresponding to the bodytemperature of the animal at periodic sampling intervals; applying analgorithm where: t_(ear) is the instantaneous ear temperature;t_(ambient) is the instantaneous ambient air temperature; d is thedifference between ear and ambient temperatures; fast is thefast-response filter element; slow is the slow response filter element;v is the integral of the difference between the two filter elements; C₁is the time constant of the fast filter; ° c₂ is the time constant ofthe slow filter; Time constants are such that c₁>C₂, 0<c₁<1,0<C_(2<1;) where initially: n=1 d₀=t_(ear)−t_(ambient) fast₀=d₀ slow₀=d₀ V₀=0  andwhere at each sampling interval: d_(n)=t_(ear)−t_(ambient)fast_(n)=(1−c₁)*fast_(n−1)+c₁*d_(n) slow_(n)=(1−c₂)*slow_(n−1)+c₂*d_(n) then: V_(n)=V_(n−1)+(fast_(n)−slow_(n)); and  comparing vn to apredetermined threshold.
 40. A system for providing an indication of atleast one of meat quality, pH levels, and stress levels in an animal tobe slaughtered, the system comprising: a body mountable measurementdevice for obtaining measurements corresponding to the body temperatureof the animal at periodic sampling intervals over a period of between336 hours; and a processor having an input means for receiving themeasurements from the measurement device, the processor operable to:determine the animal's mean body temperature from the measurements;calculate the variance between each measurement and the mean; and addall variances to obtain a cumulative variance score; wherein theprocessor has an output means for providing the cumulative variancescore.
 41. A system for providing an indication of at least one of meatquality, pH levels, and stress levels in an animal to be slaughtered,the system comprising: a body mountable measurement device for obtainingmeasurements corresponding to the body temperature of the animal atperiodic sampling intervals over a period of between 336 hours; and aprocessor having an input means for receiving the measurements from themeasurement device, the processor operable to implement an algorithmwhere: t_(ear) is the instantaneous ear temperature; t_(ambient) is theinstantaneous ambient air temperature; d is the difference between earand ambient temperatures; fast is the fast-response filter element; slowis the slow response filter element; v is the integral of the differencebetween the two filter elements; c₁ is the time constant of the fastfilter; c₂ is the time constant of the slow filter; Time constants aresuch that c₁>c₂, 0<c₁<1,0<c₂<1;  where initially: n=1d₀=t_(ear)−t_(ambient) fast₀=d₀ slow₀=d₀ v₀=0  and where at eachsampling interval: d_(n)=t_(ear)−t_(ambient)fast_(n)=(1−c₁)*fast_(n−1)+c₁*d_(n) slow_(n)=(1−c₂*slow_(n−1)+c₂*d_(n) then: V_(n)=V_(n−1)+fast_(n)−slow_(n))  wherein the processor has anoutput means for providing the result v_(n).
 42. A system for providingan indication of at least one of meat quality, pH levels, and stresslevels in an animal to be slaughtered, the system comprising: a bodymountable measurement device for obtaining measurements corresponding tothe body temperature of the animal at periodic sampling intervals over aperiod of between 336 hours; and a processor having an input means forreceiving the measurements from the measurement device, the processoroperable to implement an algorithm to the measurements, which algorithmcumulatively takes account of variations in body temperature over a timewindow, wherein the processor has an output means for providing theresult of the algorithm; wherein the system is embodied in an all-in-oneindicator device.
 43. The system as claimed in claim 42 wherein thedevice is provided in the form of an ear tag.
 44. The system as claimedin claim 43 wherein the tag incorporates the measurement device.
 45. Asystem for providing an indication of at least one of meat quality, pHlevels, and stress levels in an animal to be slaughtered, the systemcomprising: a body mountable measurement device for obtainingmeasurements corresponding to the body temperature of the animal atperiodic sampling intervals over a period of between 336 hours; and aprocessor having an input means for receiving the measurements from themeasurement device, the processor operable to implement an algorithm tothe measurements, which algorithm cumulatively takes account ofvariations in body temperature over a time window, wherein the processorhas an output adapted to output a numeric value result of the algorithmfrom a comparison with a meat tenderness scale.
 46. A system forproviding an indication of at least one of meat quality, pH levels, andstress levels in an animal to be slaughtered, the system comprising: abody mountable measurement device for obtaining measurementscorresponding to the body temperature of the animal at periodic samplingintervals over a period of between 336 hours; and a processor having aninput means for receiving the measurements from the measurement device,the processor operable to implement an algorithm to the measurements,which algorithm cumulatively takes account of variations in bodytemperature over a time window, and operable to compare the output ofthe algorithm to a predetermined threshold wherein the processor has anoutput means for providing the result of the algorithm; an indicator toindicate where the output of the algorithm has exceeded thepredetermined threshold and provide an indication that the system isfunctioning.
 47. A temperature sensing device including: a tag having anattachment portion to extend through a body part of an animal, the tagincorporating an indicator means; one or more animal temperature sensorsdisposed on/in the attachment portion for contact with the animal duringuse; an ambient temperature sensor provided on the tag; comparison meansis provided to compare the ambient temperature with the animaltemperature; an indicator is disposed on the tag, the indicator beingresponsive to the comparison means.